You can control this by using the concept of expand ratios when using Vertical and Horizontal Layouts in Vaadin. By default a vertical layout with a defined height allocate the same amount of 'slot' space to each item (in your example 50% will be allocated to top and 50% to bot. I've added a red and blue box around the top and bot portions of your layout to show that Vaadin has allocated 50% to each: